This is a multicenter, randomized, double-blind, double-dummy comparative study assessing the efficacy and safety of IV followed by oral mycophenolate mofetil or azathioprine, each in combination with cyclosporine (Neoral) and corticosteroids, in patients receiving their first cadaveric liver allograft. The primary objectives are 1) to demonstrate that mycophenolate mofetil reduces the proportion of patients who experience in the first six months posttransplantation (a) one or more epidoses of treated, biopsy-proven acute allograft rejection with biochemical abnormalities suggestive of rejection, or (b) death/retransplantation and 2) graft loss (death/retransplantation) during the first 12 months of posttransplantation. Since the patients recruited for the study are post-transplant and very ill, a GCRC nurse travels to Rochester Methodist Hospital to perform the blood draws for the pharmacokinetic studies. We had anticipated 80 patients, but enrollment has stopped. we are still following all patients.